Vacuum producing and heating apparatus



Dec. 26, 1933. J. H. WALKER 1,941,422

VACUUM PRODUCING AND HEATING APPARATUS Filed June 20. 1932 gwuc/wkwlJaw? as A- 772M 19)" Patented Dec. 26, 1933 UNITED STATES PATENT OFFICEVACUUM PRODUCING AND HEATING APPARATUS Application June 20, 1932. SerialNo. 618,351

Claims. (Cl. 257-30) This invention relates generally to water heatersand has for an object the provision of means for utilizing the heat fromsteam used in conjunction with vacuum producing devices operated bysteam, such as steam ejector cooling systems, for heating to a suitabletemperature the water discharged from said systems.

Another object is to provide a plurality of ejectors which draw from thesame vacuum tank 15 and discharge into the condensing means.

Another object is to provide a heater wherein automatically operablemeans is provided for regulating the amount of steam used for heatingthe water.

Another object is to provide a heater wherein provision is made forutilizing the heat from condensation from part of the system forstepping up the temperature-of the water while it is flowing from onepart of the system to another.

Another object is to provide a heater wherein the flow of water from onepart of the system to the other is interrupted and directed elsewherewhen the flow of water through the other part falls below apredetermined point.

Other objects, advantages and novel details of construction of thisinvention will be made more apparent as this description proceeds,.especially when considered in connection with the accompanying drawing,wherein:

The figure illustrated is a diagrammatic view of vacuum producingequipment and a heater embodying my invention.

Referring now to the drawing, A is the vacuum tank; B is the pump; C isthe cooling unit; D are v the spray nozzles; E is the steam ejector andF is the condenser of a conventional form of steam jet cooling system. Avery high vacuum or a very low absolute pressure is maintained in thetank A, preferably by means of the steam ejector E which is connected tothe tank by piping G and discharges into the condenser F. If thetemperature of the water sprayed into the tank A from the nozzles D isabove the temperature corresponding to the pressure maintained in thetank,

then a part of the water will flash into vapor. The heat required tovaporize this amount of water will be supplied by the remainder of thewater flowing through the system and the giving up of this heat resultsin a lowering of the water temperature to a point corresponding with thepressure existing in the tank. For example, if the pressure in the tankis maintained at 0.1475 pounds per square inch absolute, the water willbe cooled to approximately 45 F. If the pressure in the tank ismaintained at 0.1217 pounds per square inch absolute the watertemperature will be reduced to approximately 40 F. This relation betweenthe pressure and temperature is well known. The cold water in the tank Ais withdrawn by the pump B and circulated through the cooling unit Cwhich may consist of a coil of tubing located in the path of air whichis to be cooled. The water leaves the unit C at an increased temperatureof say 50 F. and passes thence to the spray nozzles D aforesaid. Waterpreferably having a temperature of about F. is supplied to the headers Hof the condenser F and after being heated within the condenser tubes Iis discharged through headers J at a temperature of approximately 95 F.

The amount of steam used by the ejector E is an appreciable factor inthe operating cost and heretofore the heat in that steam was largelywasted. However, in the present instance, such waste of heat is avoidedby the utilization of all or a part thereof to heat water which may beused for various purposes. In accordance with my invention I have addeda second ejector K and a second condenser L which are preferablyessentially similar to ejector E and condenser F respectively. As shownin the drawing, the ejectors K and E are arranged to operate inparallel, that is, so that each ejector has its suction side connectedto the vacuum tank so as to draw therefrom and the steam jet E, asshown, ordinarily will have a greater vacuum producing effect than thejet K. Thus part of the work in evacuating the flash tank A may beaccomplished by means of the ejector K and a portion of the water whichhas been heated to a temperature of say 95 F. in condenser F is heatedfurther in its passage through condenser L to a temperature ofapproximately 140 F. so that it can be used in lavatory fixtures,dishwashing apparatus or for industrialpurposes. In order to obtain thetemperature of 140 F. at the outlet M of condenser L the pressure ofsteam surrounding the tubes N in that condenser must be at a pressurecorresponding to a temperature of approximately 150 F. This pressure is3.716 pounds per square inch absolute and is higher than the pressuremaintained in condenser F which may be approximately 1.100 pounds persquare inch absolute. The exact values of these pressures andtemperatures are not important but the significant point is that thepressure-in condenser F is maintained as low as possible for the sake ofeconomy, whereas the pressure in condenser L must be higher.

Preferably the ejectors K and E are controlled so that ejector K is inuse only when its exhaust steam can be economically utilized for waterheating. For instance, when no steam is required at the moment to heatwater, ejector K will be cut off and ejector E used alone since itseconomy as to steam consumption is much better than that of ejector K.As shown, ejector E is controlled by a thermostatic element 0 within thetank A and actuated by the temperature of the water therein, while theejector K is controlled from a thermostatic element R located in thepipe S leading from the outlet M of the condenser L to the points ofuse. Thus when the temperature of the water in the tank A is lowered toa predetermined degree the ejector E will be automatically cut out ofservice, and when the temperature of the water flowing through the pipeS drops below a predetermined point ejector K will come into action. Asa result ejector K will be utilized only when its exhaust steam isneeded to heat water and the temperature of the water in the tank A willbe automatically maintained.

In order that the heat in the condensation from condenser L may beremoved before that condensation is wasted, I preferably utilize a heatexchanger T in the system. As shown, this exchanger comprises a casing Uthat receives water from the header J of condenser F and a coil Vlocated within the casing U and adapted to receive the condensation fromcondenser L. T is a waste pipe leading from the coil V. Thus with thisconstruction the heat from the condensation in coil V will be utilizedto heat the water in casing U from a temperature of approximately 95 F.which it has when it leaves header J of condenser F to a temperature ofapproximately 110 F. before it enters condenser L. In this manner thetemperature of the water is effectively stepped up while flowing betweenthe two condensers F and L respectively.

Inasmuch as the demand for hot water in the pipe S is oftenintermittent, whereas the flow of water through condenser F must becontinuous to give a continuous cooling effect in the tank A, I haveprovided a relief valve W in the pipe X extending between the condenserF and heat exchanger T. Preferably this relief valve W is so designedthat when the flowof water through condenser L to pipe S falls below apredetermined point the relief valve will open and permit a suflicientquantity of water to pass through condenser F to the overflow or wastepipe Z.

Thus from the foregoing it will be apparent that I have provided a veryemcient means for utilizing the heat heretofore wasted in steam ejectorcooling systems for heating water. The parts are so constructed that thesteam ejector cooling system maintains its high degree of emciency andat the same time steam will be used for heating purposes only whenneeded.

What I claim as my invention is:

1. The combination with a steam ejector cooling system including a flashtank, a condenser, and a steam ejector connected to said tank anddischarging into the condenser, of a second contors aforesaid includingthermostats associated with the flash tank and piping aforesaid.

2. The combination with a steam ejector cooling system including avacuum tank, a condenser, and a steam ejector connected to said tank anddischarging into said condenser of -a second condenser connected to andadapted to receive water from the first condenser, a steam ejectorconnected to the vacuum tank and discharging into the second condenserwhereby water therein may be heated to a suitable temperature, and meansbetween said condensers for stepping up the temperature of waterdischarged from the first mentioned condenser before it reaches thesecond mentioned condenser.

3. The combination with a steam ejector cooling system including avacuum tank, a condenser, and a steam ejector connected to said tank anddischarging into said condenser associated therewith, of a secondcondenser adapted to receive water from the first condenser, a steamejector connected to said vacuum tank and discharging into the secondcondenser whereby water therein may be heated to a suitable temperature,means for conducting water from the first mentioned condenser to thesecond mentioned condenser, and means associated with the secondmentioned condenser and the means just mentioned for stepping up thetemperature of the water from the first mentioned condenser before itreaches the second mentioned condenser.

4. The combination with a steam ejector cooling system having acondenser and a steam ejector associated therewith, of a secondcondenser for receiving water from the first mentioned condenser, asteam ejector associated with the second condenser whereby water thereinmay be heated to a suitable temperature, and piping for conducting to asuitable point the water heated in the second condenser, means forconducting water from the first mentioned condenser to the secondmentioned condenser, and relief means associated with the last mentionedmeans and operable to cut ofi the flow of water from the first mentionedcondenser to the second mentioned condenser and to permit water from thefirst mentioned condenser to be otherwise directed when the flow ofwater through the piping aforesaid from the sec-. ond condenser fallsbelow a predetermined point.

5. In a device of the class described, a vacuum tank, a pair ofcondensers arranged in series, and a pair of steam ejectors arranged inparallel with reference to the vacuum tank aforesaid and discharginginto said condensers.

6. In a device of the class described, a vacuum tank, a pair ofcondensers, a pair of steam ejectors discharging into said condensers,one into each condenser, and a conduit leading from the tank and commonto both of said ejectors.

7. In a device of the class described, a pair of condensers, means forconducting a fluid through said condensers, means including a steamejector discharging into one of said condensers for heating the fluid insaid conducting means, means associated with said conducting means forstepping up the temperature of the fluid after it reaches the firstmentioned condenser and before it reaches the second mentionedcondenser, and means including a steam ejector discharging into thesecond condenser for heating the fluid in said conducting means afterthe temperature thereof has been stepped up.

8. In a device of the class described, a vacuum tank, a condenser, asteam ejector discharging into said condenser, a second condenser, asteam means connecting the suction sides of the ejectors with the tank,and control means for said ejectors including means for shutting off oneof them without interfering with the operation of the other. 4

9. In a device of the class described, a vacuum tank, a condenser, meansincluding a steam ejector for heating fluid in said condenser, a secondcondenser, means for conducting the heated fluid from the firstcondenser to the second condenser, means including a second steamejector for heating the heated fluid in the second condenser, piping forconducting to a suitable point the heated fluid from the secondcondenser, means connecting the suction sides of the ejectors with thetank, and control means for the ejectors associated with the tank andpiping.

10. In a device of the class described, a vacuum tank, a condenser,means including a steam ejector for heating fluid in said condenser, asecond condenser, means for conducting the heated fluid from the firstcondenser to the second condenser, means including a second steamejector for heating the heated fluid in the second condenser, piping forconducting to a suitable point the heated fluid from the secondcondenser, means connecting the suction sides of the ejectors with thetank, and means associated with the conducting means aforesaid andoperable to cut off the flow of fluid from the first condenser to thesecond condenser when the flow of fluid through the piping aforesaidfalls below a predetermined point.

11. In a device of the class described, a vacuum tank, condensing means,a pair of steam ejectors connected in parallel and discharging into saidcondensing means, and means connecting the suction side of said ejectorsto said vacuum tank.

12. In a device of the class described, a vacuum tank, a pair ofcondensers, a pair of steam ejectors discharging in parallel into saidcondensers, one into each condenser, and means connecting the suctionsides of said ejectors to said vacuum tank.

13. In a device of the class described, a vacuum tank, a pair ofcondensers, a pair of steam ejectors-discharging into said condensers,one intoeach condenser, and means leading from the tank to saidejectors. v

14. In a device of the class described, a vacuum tank, condensing means,and a plurality of steam ejectors discharging into said condensingmeans, the suction sides of said ejectors being connected to and drawingfrom said vacuum" tank.

15. In a device of the class described, a vacuum tank, a pair ofcondensers, and a pair of steam ejectors discharging in parallel intosaid condensers, one into each condenser, the suction sides of saidejectors being connected to and drawing from said vacuum tank.

JAMES H. WALKER.

